DE 297 07 562 U1 describes a motor vehicle seat in which the retaining rods of its headrest fit into a nonreclining sleeve and are vertically adjustable therein. The sleeve features a sleeve head with which it forms one piece in which a rectangular frame in the form of a drawer is inserted and mounted at right angles to the longitudinal axis of the retaining rod as an arresting means. This frame features a foot, which locks into engagement with any of the arresting notches of the retaining rod of the headrest. The locking of the frame is ensured by springs, which abut both the frame and the sleeve head. In an embodiment, the retaining rod, that is the headrest, is released by means of a manual control element, which presses the frame against the force of the spring out of its locked position to allow the height of the headrest to be adjusted. The retaining rod engages both the sleeve head as well as the locking frame and can be moved in axial relation thereto.
The locking frame is made of a synthetic material and, as an injection molded part, entails a relatively time-consuming manufacturing process. Furthermore, this height adjustment mechanism of the headrest of a motor vehicle seat from the prior art can still be further simplified, despite having an already simple design.
The height adjustment mechanism described EP 1 046 541 A1 represents just such a simplification. In this particular seat, the retaining rods of the headrest as well as portion below featuring arresting notches fit into a nonreclining socket. An arresting means is present, which is realized as a spring with a retaining foot and an arresting foot and is mounted on a nonreclining base integrated into the top surface of the backrest. The spring abuts the base with its retaining foot and, in locked position, rests with its arresting foot engaging an arresting notch of the retaining rod as a result of spring tension. The free end of the arresting foot projects from the base and features a manual operating button in the form of a bulge. For headrest height to be lowered, the manual operating button of the arresting foot must be pivoted to the side, whereby the arresting foot is freed from the arresting notch of the retaining rod with which it was engaged.